source: trunk/sample/miscellaneous/sample_discontinuities.mso @ 488

#*-------------------------------------------------------------------
* EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC.
*
* This LIBRARY is free software; you can distribute it and/or modify
* it under the therms of the ALSOC FREE LICENSE as available at
* http://www.enq.ufrgs.br/alsoc.
*
* EMSO Copyright (C) 2004 - 2007 ALSOC, original code
* from http://www.rps.eng.br Copyright (C) 2002-2004.
* All rights reserved.
*
* EMSO is distributed under the therms of the ALSOC LICENSE as
* available at http://www.enq.ufrgs.br/alsoc.
*
*--------------------------------------------------------------------
* FlowSheet showing how to use the 'if' conditional.
* Ref: M.B. Carver (1978). Mathematics and Computers in Simulation
*      v.20, pp.190-196
*--------------------------------------------------------------------
* Author: Arge
* $Id: $
*--------------------------------------------------------------------*#

FlowSheet Carver1
        VARIABLES
        x as Real;
        u as Real;

        EQUATIONS
        u = sin(8*asin(1)*time*'rad/s');
        
        if u > 0 then
                diff(x) * 's' = x^2;
        else
                diff(x) * 's' = 0;
        end

        INITIAL
        x = 0.1;
        
        OPTIONS
#       TimeStep = 0.9; # for statistical purpose (Detailed Output)
        TimeStep = 0.01; # for graphical purpose
        TimeEnd = 0.9;
        TimeUnit = 's';
        DAESolver  (File = "dasslc",
                                RelativeAccuracy = 1e-6,
#                               RelativeAccuracy = 1e-4,
                                AbsoluteAccuracy = 1e-6);
end

FlowSheet Carver2
        PARAMETERS
        eps as Real (Default=1e-5);
        
        VARIABLES
        x as Real;
        u as Real;
        n as Real;

        EQUATIONS
        u = sin(8*asin(1)*time*'rad/s');
        
        n = 0.5 * (1 + tanh(-u/eps)); # regularization function
        
        diff(x) * 's' = x^2 * (1-n);

        INITIAL
        x = 0.1;
        
        OPTIONS
#       TimeStep = 0.9; # for statistical purpose (Detailed Output)
        TimeStep = 0.01; # for graphical purpose
        TimeEnd = 0.9;
        TimeUnit = 's';
        DAESolver  (File = "dasslc",
                                RelativeAccuracy = 1e-6,
#                               RelativeAccuracy = 1e-4,
                                AbsoluteAccuracy = 1e-6);
end

FlowSheet Carver3
        PARAMETERS
        eps as Real (Default=1e-5);
        
        VARIABLES
        x as Real;
        u as Real;
        n as Real;

        EQUATIONS
        u = sin(8*asin(1)*time*'rad/s');
        
        n = 0.5 * (1-(u/eps)/(sqrt(1+(u/eps)^2))); # regularization function
        
        diff(x) * 's' = x^2 * (1-n);

        INITIAL
        x = 0.1;
        
        OPTIONS
#       TimeStep = 0.9; # for statistical purpose (Detailed Output)
        TimeStep = 0.01; # for graphical purpose
        TimeEnd = 0.9;
        TimeUnit = 's';
        DAESolver  (File = "dasslc",
                                RelativeAccuracy = 1e-6,
#                               RelativeAccuracy = 1e-4,
                                AbsoluteAccuracy = 1e-6);
end

FlowSheet Carver4
        VARIABLES
        x as Real;
        u as Real;

        EQUATIONS
        
        if x > 0.5 then
                u = 0.5;
        else if x < -0.5 then
                        u = 0.2;
                 else
                        u = 1.0;
                 end
        end

        diff(x) * 's' = -u*x + sin(time*'rad/s');

        INITIAL
        x = 0.0;

        OPTIONS
        TimeStart = 3.1415/4;
#       TimeStep = 12.5-3.1415/4; # for statistical purpose (Detailed Output)
        TimeStep = 0.01; # for graphical purpose
        TimeEnd = 12.5;
        TimeUnit = 's';
        DAESolver  (File = "dasslc",
                                RelativeAccuracy = 1e-4,
                                AbsoluteAccuracy = 1e-6);
end

FlowSheet Carver5
        PARAMETERS
        eps as Real (Default=1e-5);
        
        VARIABLES
        x as Real;
        u as Real;
        n1 as Real;
        n2 as Real;
        
        EQUATIONS

        n1 = 0.5 * (1 + tanh((x-0.5)/eps)); # regularization function
        n2 = 0.5 * (1 + tanh(-(0.5+x)/eps)); # regularization function

        u = n1*(1-n2)*0.5+n2*(1-n1)*0.2+(1-n1)*(1-n2);

        diff(x) * 's' = -u*x + sin(time*'rad/s');

        INITIAL
        x = 0.0;

        OPTIONS
        TimeStart = 3.1415/4;
#       TimeStep = 12.5-3.1415/4; # for statistical purpose (Detailed Output)
        TimeStep = 0.01; # for graphical purpose
        TimeEnd = 12.5;
        TimeUnit = 's';
        DAESolver  (File = "dasslc",
                                RelativeAccuracy = 1e-4,
                                AbsoluteAccuracy = 1e-6);
end

FlowSheet Carver6
        PARAMETERS
        eps as Real (Default=1e-5);
        
        VARIABLES
        x as Real;
        u as Real;
        n1 as Real;
        n2 as Real;
        
        EQUATIONS

        n1 = 0.5 * (1+((x-0.5)/eps)/(sqrt(1+((x-0.5)/eps)^2))); # regularization function
        n2 = 0.5 * (1-((0.5+x)/eps)/(sqrt(1+((0.5+x)/eps)^2))); # regularization function

        u = n1*(1-n2)*0.5+n2*(1-n1)*0.2+(1-n1)*(1-n2);

        diff(x) * 's' = -u*x + sin(time*'rad/s');

        INITIAL
        x = 0.0;

        OPTIONS
        TimeStart = 3.1415/4;
#       TimeStep = 12.5-3.1415/4; # for statistical purpose (Detailed Output)
        TimeStep = 0.01; # for graphical purpose
        TimeEnd = 12.5;
        TimeUnit = 's';
        DAESolver  (File = "dasslc",
                                RelativeAccuracy = 1e-4,
                                AbsoluteAccuracy = 1e-6);
end